Combustion of fuel, particularly carbonaceous materials such as fossil fuels and waste, results in flue gas streams that contain impurities, such as mercury (Hg), sulfur oxides (SOx), nitrogen oxides (NOx), and particulates, such as fly ash, which must be removed or reduced to a more acceptable level prior to releasing the flue gas to the environment. In response to regulations in place in many jurisdictions, numerous processes and apparatuses have been developed to remove or reduce the levels of impurities and particulates in the flue gas.
The typical method of reducing flue gas particulates, Hg, NOx, and SOx impurities from steam generating boilers powered by fuel combustion is by the use of flue gas treatment equipment. Such equipment includes electrostatic precipitators (ESP), fabric filter bag houses, catalytic systems, wet flue gas desulfurization systems and/or dry flue gas desulfurization systems (referred to as WFGD and DFGD respectively).
In some flue gas stream processing systems, removal of acidic components, such as SOx, is facilitated through the use of a DFGD system, wherein a reagent slurry or solution contacts the flue gas stream and reacts with the SOx present therein. Current DFGD systems utilize spray dryer absorbers having an atomizer system that receives the reagent slurry, typically in combination with a dilution liquid.
Delivery of the reagent slurry or solution to the atomizer system in combination with the dilution liquid results in scale buildup in the delivery hose. Scale buildup results in shut down of the plant or system for necessary cleaning and maintenance. As will be appreciated, plant or system shut down, as well as the related cleaning and maintenance of the system and/or plant, is time consuming and costly. Accordingly, a system and process for reducing scale buildup in an atomizer system would result in fewer plant or system shut-downs for cleaning and maintenance purposes.